ABSTRACT
This chapter describes the insecticidal proteins, summarizes much of the literature on their use in crop protection, and discusses the potential for improving their efficacy. Insecticide usage by pest order shows that Lepidoptera are the major target for insecticides, followed by Homoptera, Coleoptera and Mites. Plants are protected from insect and pathogen attack by many different defense mechanisms, but perhaps the most important are chemically based. Much work has been carried out to identify sources of resistance for use in crop breeding programs. Protease inhibitors can essentially be divided into four categories: those that specifically inhibit the serine proteases, the sulphyldryl proteases, the metallo carboxypeptidases, and the acid proteases. Multiple mechanisms of resistance in a single crop would be highly advantageous in the field, resulting in more durable resistance compared with that conferred by single genes. Although genetic engineering will assist in protecting crops, global plant genetic resources will remain vital to plant breeding in the future.
